It's a new week and I should, really, start a new conversation. There is a powerful Full Moon tonight and tomorrow and I certainly must not forget to alert everyone to that. Still, though, I can't get that Russian 'space mission' out of my mind. Are they really going to lock six people into a steel box for 18 months and make them imagine they are heading for Mars? Are there other uses for this idea? Could we, for example, save on carbon emissions by getting holidaymakers to enter a stationary plane and pretend they were going abroad?

Once, a month was 29.5 days long, because that's roughly how long it takes to get from one full moon to the next. Early civilisations matched movements of the Moon with the Sun's yearly pattern, creating stone circles, such as Callanish in Scotland, to mark this 19-year cycle. Later, the Romans simplified this system, resulting in our modern, clumsy calendar. So why, with all today's technology, don't we just do away with all that and get back to a more natural rhythm? Maybe when we wish on the Full Moon tonight, we should add that to the list!

You can't tell by looking but, technically, the Moon is beginning to wane. Do vampires, though, consult astronomical tables before rising from their coffins? And have you ever seen a werewolf clutching a calculator? While the Moon looks full, it remains an invitation to shape-shifters. They may not all, though, be people turning into creatures. In Japanese tradition, this time of the month is when Kitsune and Tanuki, the smart fox and clever raccoon, are most likely to take human form. Meanwhile, modern astrologers are more inclined to expect situations, rather than people or animals, to suddenly transform.

Legends about shape-shifters say much about our fears and fantasies. While vampires and werewolves are depicted as monsters, not all stories are bleak. A Japanese tale involves a man called Ono, who married a fox, disguised as a beautiful woman. One day, she gave birth. And, later, their dog had a puppy who attacked her. She changed back into a fox and ran away. Ono called out, 'You may be a fox, but you're the mother of my son. I love you. Please feel free to return.' So every evening she stole back and slept in his arms.

Apparently, during The Wonders Of The Solar System on BBC2, the presenter described astrology as rubbish. I wonder if he feels the same way about love, God or life after death? These too, are ideas that people are entitled to place their faith in, even if scientists have yet to find proof. When the learned host of an educational programme declares a personal opinion as if it were an incontrovertible fact, isn't he abusing his position of authority? The Astrological Association of Great Britain have asked me to encourage as many people as possible to complain to the BBC. You can contact the BBC complaints department

Mercury and Venus are now close, in the West, after sunset. Officially, they're not in exact conjunction. It is as if Mercury, the heavenly messenger, is rushing towards Venus with a question. It gets within shouting distance and hangs around, seemingly awaiting an answer. Then, rather than overtake Venus, it backs away... in order to be well positioned for a harmonious alignment to Pluto early in May. Then it will take Pluto's 'comments' back to Venus... early in July. April, therefore, brings us a retrograde Mercury, with all the difficulties in transport and communication that such phases traditionally trigger.

Mercury and Venus are nearer to the Sun than we are. That's why, when we see them, they are always in the same part of the sky that the Sun is in. That's also why, when they are visible, it's always at dusk or dawn. Look out, in mid-April, for Venus near the crescent moon at nightfall. Mars and Saturn are on show all month long and around April 21, there's a quarter moon in the late afternoon, followed by shooting stars into the night. Don't forget to make a wish when you see these!

Some astrologers specialise in sport. They make reliable, regular predictions. You won't though, read their words in print. The only place they ever write up their predictions is on a betting slip! I don't dabble in such divination. I'm not interested in gambling... or upsetting people. What if I were to suggest that England were due to do badly in the World Cup? The fans wouldn't want to hear it. Nor would the team. So I must keep well out of football matches. So, too, this summer, must David Beckham. He may not be glad about his injury but for his status as an international superstar, it's a blessing. He gets reflected glory if they succeed. He's blameless if they fail. David is a Taurean and all born under this sign are being blessed with supportive stars now, even if they can't immediately see this.